Content providers often capture moving-images content (e.g., video or digital film) at a defined frame rate and store the resulting frames on media for subsequent playback. They also frequently capture such content in frames for real-time streaming, broadcast, etc. It has been found that such content, if captured and processed at certain “cinematic” frame rates, usually produces satisfactory moving images (hereinafter simply “images”) when displayed at those cinematic frame rates and when no disturbances interfere with the distribution or display of that content.
Indeed, with the advent of high quality, high fidelity, high definition (HD), and/or premium quality content, many providers capture such content at cinematic frame rates of 23.976/24.000 fps and 25.000 fps (hereinafter 24 fps and 25 fps respectively) among others. For instance, some HD systems capture content at 24 fps using a “1080p” (1080 lines of resolution per frame in progressive “p”) format. A non-limiting but common example of such content is a Blu-Ray Disc® movie.
Unfortunately, many conventional display systems and their pipeline components process and present moving-images content at a different rate than the cinematic frame rate. Indeed, many displays operate on or about a default screen refresh rate of 60 Hz, rather than one of the many available cinematic frame rates. This is particularly true of conventional displays often used in conjunction with personal computers (PCs) that can at times simultaneously support a variety of content types and rates, in addition to cinematic content. As a result, the transmitters (and/or wired connectors) in many PCs and other devices often transmit at a default rate of 60 Hz, even in cases where the display can more optimally support 24 Hz. This is due to the lack of a mechanisms to automatically identify and adapt to cinematic content when it is being presented.
To account for such rate mis-matches and the lack of ability to identify when cinematic content is being presented, digital display system components (e.g., PCs, displays, etc.) up-convert to operate at the display's default refresh rate (e.g., 60 Hz) by inserting duplicates of the individual frames of cinematic frame-rate content into the to-be-displayed content using a patterned sequence. However, a pipeline of content-processing components often lies between the media containing the content (or a source generating the content) and the display. Many of these components possess limitations and/or preferred frame rates, protocols, buffering schemes, etc. that might not be entirely compatible with, knowledgeable of, or adjustable to the content's cinematic frame rate, and they might not even be compatible with the refresh rate of the display itself and/or the native frame rate of other pipeline components.
Thus, frame rate mis-matches and de-synchronizations can occur in the pipeline that cause undesired duplicate frames, dropped frames, torn frames, judder-related effects, etc. in the resulting moving images presented to the viewer by the display. Instead of a smoothly flowing image, therefore, many conventional displays sometimes present “jerky” images (images which exhibit effects of phenomenon commonly and collectively referred to as “judder”).
Moreover, some conventional systems attempt to overcome the foregoing effects by driving their displays at the higher rates native to the displays (or at even higher frame rates). This approach assumes that if the display is driven at a sufficiently high rate, some of the problems associated with the jerky images decrease. However, some duplicate, dropped, and/or possibly torn images will still occur because of the lack of synchronization between the various pipeline components between (and including) the media players and the displays. Moreover, some pipeline components might have difficulty keeping pace with the higher display refresh rate. For example, one of the pipeline content-processing components upstream of the display could be limited to 30 Hz operation, thereby preventing or severely limiting the ability of the pipeline to account for rate mis-matches, regardless of the downstream display's higher rate capabilities.
When lower frame rate content is being presented, driving the display and pipeline components at such high frame rates consumes more electrical power, computing power (i.e., processing, memory, etc.), and communications link bandwidth throughout the pipeline as compared with operating at lower rates. The presence of battery powered and/or wireless devices (for instance, laptop personal computers or PCs and wireless displays) aggravate the foregoing effects. Video encoding, decoding and encryption and other schemes used to secure the digital rights of the content providers further aggravate the situation since these techniques require comparatively intense processing. Furthermore, because of those processing demands in part, these operations increase the likelihood of upsets throughout the pipeline.
The Detailed Description references the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.